Sawfish Facts

Sawfish Biology

 


Sawfish are unique elasmobranchs (the sharks, rays and skates) that possess a large toothed rostrum, or saw as it is commonly called. Sawfish are rays that inhabit nearshore waters in tropical, subtropical and warm-temperate regions of the world. The body is flattened and they spend much of their time lying on the sea bottom. They are able to breathe while lying on the bottom by drawing in water to their gills through spiracles (large holes located behind the eyes).

Sawfish are often confused with sawsharks, which also have saws. However, sawfish are a species of ray and have their gills located on the underside of their bodies. Sawsharks are a shark and have their gills on the sides of their bodies.

The rostrum, or saw, is used to catch and kill food. Small sawfish use the saw to grub on the bottom and uncover small crustaceans and fish. Large sawfish swim through schools of fish (jacks, mullet, ladyfish) and swipe the saw through the school, stunning or impaling fish. Sawfish have been observed wiping their saws on the bottom, removing fish that have been impaled on the teeth of the rostrum.

In Florida, newborn sawfish are about 2 feet long. It is believed that males reach sexual maturity at 10-11 feet and females at 11-12 feet. The largest size normally observed is 18 feet.

Very little is known about the age and growth of sawfish, the litter sizes (believed to be 10-20 young), how often sawfish mate and bear young, and the mating and pupping seasons. It is known that shallow estuarine areas are important habitat that act as a protective nursery for small, young sawfish.

Sawfish Species

Sawfish belong to the family Pristidae, within the order Pristiformes. There are seven recognized species of sawfish worldwide. Some species are very similar and research currently under way may show that there are really fewer species than now believed.

The genus Pristis has six currently recognized species that can be divided into two similar groups:

1. The Pristis group - characterized by a broad tapering rostrum with a small number of teeth (15-20 per side) and a "preference" for freshwater. The status of each of these species remains to be solved, and may be found to all be the same species.

  • Pristis pristis (common sawfish): found in northwest Africa and the Mediterranean. Critically endangered on the IUCN Red List.
  • Pristis perotteti (largetooth sawfish): found in the Atlantic and eastern Pacific Oceans. Critically Endangered on the IUCN Red List.
  • Pristis microdon (freshwater sawfish): found in the Indo-West Pacific including northern Australia. Critically Endangered on the IUCN Red List.

2. The Pectinata group - characterized by a non-tapering rostrum with many teeth (22-32 per side) and a reduced "preference" for freshwater (although they can still tolerate freshwater for extended periods). The distinction between these species is relatively well defined and these species should remain valid.

  • Pristis pectinata (smalltooth sawfish): found in the Atlantic, Indian and western Pacific Oceans. Critically Endangered on the IUCN Red List.
  • Pristis clavata (dwarf sawfish): found in tropical Australia. Critically Endangered on the IUCN Red List.
  • Pristis zijsron (green sawfish): found in the Indo-West Pacific. Critically Endangered on the IUCN Red List.

The genus Anoxypristis has one currently recognized species with a narrow saw and more flattened and triangular teeth on the rostrum than the other six species:

  • Anoxypristis cuspidata (narrow or knifetooth sawfish): found in the Indo-West Pacific. Critically Endangered on the IUCN Red List.

U.S. Population History

Early accounts of elasmobranch fauna along the East Coast of the United States and in the Gulf of Mexico reported that smalltooth sawfish were abundant in coastal and estuarine areas. They were so common that one account from the late 1800s reported a fisherman on the Indian River in Florida caught more than 300 sawfish in one season. Large sawfish are also known to have migrated north along the east coast during summer as far north as New York, but more frequently to the Carolinas. Today, however, the population of smalltooth sawfish in the United States has been severely depleted. A survey of the Indian River system published in the early 1980s reported that sawfish had probably been extirpated from that system, where they had once been so common. This scenario is repeated in most areas throughout the sawfish's historic range. Three factors have been important in the decline of the population:

  1. Fishing: Sawfish were easily caught in a variety of fishing gear, including gillnets and trawl nets, and are difficult to remove safely without killing the sawfish or cutting off the rostrum. Recreational fishers also regularly caught sawfish and their saw was a prized trophy. While rarely targeted by commercial or recreational fishers, decades of by-catch mortality decimated the population.
  2. Habitat Loss: Shallow coastal and estuarine areas are important for sawfish survival, especially for small, young animals. Extensive coastal development (dredging, mangrove removal, seawall construction, alteration of freshwater flow) throughout the smalltooth sawfish's range has meant there are fewer places for them to live.
  3. Low Reproductive Ability: Like many sharks, sawfish have a low reproductive rate because they grow slowly, mature at a late age and produce few young per litter. Therefore, when subject to fishing pressure and habitat loss, the population is unable to reproduce itself quickly enough stem the decline. It also means that the population will take a long time to recover even after proper conservation measures are in place.
Map courtesy of George Burgess (Florida Museum of Natural History)
Today, smalltooth sawfish are mostly found in the waters off Southwest Florida, especially the remote sections along the Everglades National Park, Ten Thousand Islands and Florida Keys. While it is difficult to estimate the exact numbers of sawfish remaining in U.S. waters, it is likely that the population has declined at least 95% since 1900, and most likely much more.

 

Conservation Efforts

In response to the severe decline in the smalltooth sawfish population in the western Atlantic, the species has been listed as Critically Endangered by the World Conservation Union's Shark Specialist Group and included in the Red List of Threatened Animals. In 1992, Florida completely protected sawfish within state waters, establishing zero commercial and recreational fishing bag limits.

In 1999, the Ocean Conservancy (then the Center for Marine Conservation) petitioned the National Marine Fisheries Service (NMFS) to protect the smalltooth and largetooth sawfish under the federal Endangered Species Act (ESA). In 2000, NMFS returned a finding that the petition contained information that may indicate the need for ESA listing and established a Status Review Team to review all information related to the status of sawfishes in U.S. waters. The status review team determined that the data indicated a need to protect the smalltooth sawfish population (there was no evidence found that the largetooth sawfish still exists in U.S. waters). In 2001, NMFS published a proposed rule to list the smalltooth sawfish as Endangered under the ESA and opened a 90-day public comment period. On April 1, 2003 the smalltooth sawfish was listed as Endangered under the ESA, making it the first elasmobranch to be included on the list.

This listing under the ESA recognizes the depleted state of the population, provides better protection to the smalltooth sawfish and its habitats throughout the United States and establishes the framework for developing conservation actions to recover the species. A Smalltooth Sawfish Recovery Team was formed to develop a recovery plan to save the species from extinction. A Smalltooth Sawfish Recovery Implementation Team was then formed to monitor the recovery of the species.

In June 2007, the Convention on International Trade in Endangered Species (CITES) granted trade protection to all species of sawfish, banning the international trade of sawfish and their saws and fins. Limited trade of live sawfish from Australia for public aquarium display is still allowed.

 

   
   
   

 

    REPORT SAWFISH ENCOUNTERS

    Submit your Sawfish Encounters to the
    National Sawfish Encounter Database:
    Florida Museum of Natural History
    Florida Program for Shark Research
    P.O. Box 117800
    Gainesville, Florida 32611-7800
    Phone: 352-392-2360